Theoretical or fictional cloaking devices and invisibility cloaks contemplate the use of stealth technologies to causes objects to be partially or wholly invisible to portions of the electromagnetic (EM) spectrum. Theoretical “invisibility cloaks” have been part of the scientific landscape for many years (and fictional ones for many years more). As such, there has been a significant amount of research done on “invisibility cloaks” for microwave and visible light, and various approaches have been developed. However, these prior approaches have significant limitations. By way of example, Reynolds et al., U.S. Pat. No. 8,909,385 discloses an infrared (IR) signature matching system including a heating and cooling device, a plurality of sensors configured to detect information related to the IR signature of the heating and cooling device and a background environment, a controller operably coupled with the heating and cooling device and the plurality of sensors. The controller is configured to receive the information from the plurality of sensors and adjust the temperature of the heating and cooling device until the IR signature of the heating and cooling device and the IR signature of the background environment are at least substantially matched in a selectable sub-region of the IR spectrum. It can be appreciated that the IR signature matching system disclosed in the '385 patent is complicated and expensive to implement.
Alternatively, materials have been developed to cloak the infrared signature of a heat source. By way of example, Johansson, U.S. Pat. No. 4,615,921 discloses a camouflage material having thermal emission characteristics that are predetermined to match closely the known thermal emission characteristics of the natural environment in which the particular camouflage material is intended to be used. This control is accomplished by the combination of a reflecting thin metallic layer covered on at least the exposed side by a layer of plastic including at least two different plastic materials each having respectively different emissivity properties. The reflecting layer both minimizes the heating of the camouflage material from sources covered by the material and reflects incident heat from meteorological sources, such as solar warming. The plastic layer controls and determines the radiation of heat from all parts of the exposed surface of the camouflage in order to present to surveillance equipment a thermal-picture closely simulating that of the surrounding terrain. It can be appreciated that while the thin metallic layer reflects the IR signature, the reflected IR signature adds noise to the background and could potentially give away the location of an object. Further, any metal surface may be detected due to reflection by lowlight cameras using photon multiplier tubes (PMTs).
Therefore, it is a primary object and feature of the present invention to provide a device for camouflaging an object from infrared and low light cameras.
It is a further object and feature of the present invention to provide a device for camouflaging an object from infrared and low light cameras that reduces or eliminates noise which may potentially give away the location of an object.
It is a still further object and feature of the present invention to provide a device for camouflaging an object from infrared and low light cameras that is simple to utilize and inexpensive to manufacture.
In accordance with the present invention, a device is provided for camouflaging an object from an infrared detection apparatus. The device includes a cloak positionable between the object and the infrared detection apparatus. The cloak includes a layer of infrared absorptive material having an outer surface directable towards the detection apparatus and an inner surface. A substrate has a first surface operatively connected to the inner surface of the layer and a second surface. An array of infrared emitters is operatively connected to the second surface. The array of infrared emitters selectively radiates an infrared pattern to disguise the object to the infrared detection apparatus.
The substrate is flexible and may include a heat dissipation arrangement for dissipating heat generated by the cloak during operation. The heat dissipation arrangement includes a channel formed in the flexible substrate. The channel is adapted for receiving a cooling fluid therein. The heat dissipation arrangement further includes a pump for recirculating the cooling fluid through the channel. A processing unit is operatively connected to the pump for selectively controlling operation of the pump. In addition, the processing unit may be operatively connected to the array of infrared emitters for selectively actuating each infrared emitter of the array of infrared emitters so as to cause the array of infrared emitters to radiate the infrared pattern.
The layer of infrared absorptive material includes a plurality of silicon nanowires positioned adjacent to each other. Each silicon nanowire of the plurality of silicon nanowires includes a terminal first end partially defining the outer surface of the layer and a second end. The second end of each silicon nanowire of the plurality of silicon nanowires has a generally conical configuration and terminates at a tip. The tip at the second end of each silicon nanowire of the plurality of silicon nanowires partially defines the inner surface of the layer of infrared absorptive material.
In accordance with a further aspect of the present invention, a device is provided for camouflaging an object from an infrared detection apparatus. The device includes a cloak positionable between the object and the infrared detection apparatus. The cloak includes a layer of infrared absorptive material including a plurality of silicon nanowires. The layer has an outer surface directable towards the detection apparatus and an inner surface. A substrate has a first surface operatively connected to the inner surface of the layer and a second surface. The substrate includes a heat dissipation arrangement for dissipating heat generated by the cloak during operation. An array of infrared emitters is operatively connected to the second surface. The array of infrared emitters selectively radiates an infrared pattern to disguise the object to the infrared detection apparatus.
The substrate is flexible and the heat dissipation arrangement includes a channel formed in the flexible substrate. The channel is adapted for receiving a cooling fluid therein. The heat dissipation arrangement further includes a pump for recirculating the cooling fluid through the channel. A processing unit operatively connected to the pump for selectively controlling operation of the pump. The processing unit may also be operatively connected to the array of infrared emitters for selectively actuating each infrared emitter of the array of infrared emitters so as to cause the array of infrared emitters to radiate the infrared pattern.
Each silicon nanowire of the plurality of silicon nanowires includes a terminal first end partially defining the outer surface of the layer and a second end. The second end of each silicon nanowire of the plurality of silicon nanowires has a generally conical configuration and terminates at a tip. The tip at the second end of each silicon nanowire of the plurality of silicon nanowires partially defines the inner surface of the layer of infrared absorptive material.
In accordance with a still further aspect of the present invention, a device is provided for camouflaging an object from an infrared detection apparatus. The device includes a layer of infrared absorptive material including a plurality of silicon nanowires. The layer has an outer surface directable towards the detection apparatus and an inner surface. A flexible substrate has a first surface operatively connected to the inner surface of the layer and a second surface. An array of infrared emitters is operatively connected to the second surface. The array of infrared emitters selectively radiates an infrared pattern to disguise the object to the infrared detection apparatus. A processing unit is operatively connected to the array of infrared emitters for selectively actuating each infrared emitter of the array of infrared emitters so as to cause the array of infrared emitters to radiate the infrared pattern.
The substrate includes a channel formed in the flexible substrate. The channel is adapted for receiving a cooling fluid therein. A pump operatively connected to the channel and is adapted for selectively recirculating the cooling fluid through the channel. The pump is operatively connected to the processing unit. The processing unit is configured for selectively controlling operation of the pump.
Each silicon nanowire of the plurality of silicon nanowires includes a terminal first end partially defining the outer surface of the layer and a second end. The second end of each silicon nanowire of the plurality of silicon nanowires has a generally conical configuration and terminates at a tip. The tip at the second end of each silicon nanowire of the plurality of silicon nanowires partially defines the inner surface of the layer of infrared absorptive material.